Their online shop is also great! Unfortunately it's only in Japanese though.
The 2 images below are from their website."DO" is actually in a design hotel called CLASKA, it looks really nice - I will post about it later!
The WONDERFUL Baden Baden I also visited last week is in the same area of Gakugeidaigaku though it's not really that easy to find the way between the two shops. (It's about 15 minute walk in the residential area, if you are good at reading maps you'll be fine.)
Gallery & Shop "DO" at CLASKA (3rd Floor)
1-3-18 Chuo-cho Meguro-ku Tokyo
See access information here.